If you need to print anything out, you should go to 'table of links' and select a 'pdf' file,
or otherwise from the same table you can print out individual web pages. This is just the first 4 pages of the paper handout.

Lectures on: Evolution and Psychology

Aims: These two lectures aim to refresh students' knowledge of
the theory of evolution, or to introduce them to it,
and to introduce them to aspects of psychology which have been influenced by evolutionary
approaches.

Objectives: By the end of the lectures the students should:

know the general outlines of the theory of evolution and the time course of human
evolution

be able to answer correctly a majority of the questions on the self-assessment test included in the
handout

understand some of the key differences between nativist and empiricist theories in
psychology

be aware of the sections of the course text (Gleitman, 1999) where evolutionary approaches are
applied to perceptual, cognitive, emotional and
social aspects of psychology.

From TOPIC 6 in the Seminar List —

Essay Question:

Does the theory of evolution have any relevance for psychological topics?

The Darwinian theory of evolution by natural
selection is covered on page 406-9 of Gleitman (1999) or page 416 of Gleitman et al. (2004). A key feature is that there are inherited
differences between individuals. From Darwin onwards, it has
usually been assumed that inherited differences will apply to
instinctual behaviours as well as bodily structures.

2. What do Darwinians say about psychological topics?

Darwinians therefore typically emphasise
innate or “built-in” factors as influences on psychological
capacities or behaviour patterns. They emphasise “nature” instead
of “nurture” and therefore tend to be “nativists” rather than
“empiricists”.

3. Schools of thought influenced by the Darwinian
approach.

“Ethology” has been defined as the scientific study of
the function and evolution of patterns of animal behaviour. This
area of study is associated with Niko Tinbergen (1907-1988) and
Konrad Lorenz (1903-1989) who both won the Nobel prize for their
work in 1973 (See Gleitman, 1999, p 408). They suggested that
many aspect of behaviour of animal species in their natural
environments could be explained by “Innate Releasing Mechanisms”,
by which genetically pre-programmed releasing stimuli could
elicit inherited fixed action patterns of instinctive
behaviour. The releasing stimuli are often very imprecise, and a
Supernormal Stimulus is an artificial stimulus which is more
effective at releasing instinctive behaviour than any natural
stimulus.

There are many examples, especially in the behaviour of new-
born birds, where evidence for such mechanisms is strong. It was
always more controversial to apply similar concepts to aspects of
human behaviour such as emotional expression. (see “Ethology and
Human Nature”, Gleitman, 1999 p. 437; Lorenz, 1967; Morris,
1967).

“Sociobiology” was a term coined by E.O. Wilson in 1975
to describe a branch of biology which focuses on the evolutionary
basis of animal social behaviours. It deals more with strategies
of social behaviour rather that the individual lock-and key
mechanisms studied by ethologists, but there is no firm boundary
between ethology and sociobiology. As for ethology, there has
been strong disagreement with the idea that principles derived from
animal behaviour can be applied to the human case, in “Human
Sociobiology” (see “Mating patterns in humans”, Gleitman, 1999 p.
424).

“Evolutionary Psychology”. This is a more recent
term, which has come into use in the 1990’s but is not referred to
explicitly in Gleitman et al. textbooks. There is some overlap with
ethology and sociobiology, but the emphasis in evolutionary
psychology is on the special effects of human evolution on human
psychology rather than on generalizing from animals to humans. A
very strong case can be made that the human species is genetically
pre-programmed to use language and “Evolutionary psychology
takes many of the lessons of human language and applies them to the
rest of the psyche (Pinker, 1994; p. 410). The emphasis on
language and reasoning means that the interaction between innate
and cultural factors can in principle be given due weight.
(Tomasello et al; 1993). The two names most often associated with
evolutionary psychology are Leda Cosmides and John Tooby (e.g.
Tooby and Cosmides, 1992, Duchaine et al., 2001; Stone et al.,
2002 — See
Gleitman et al., 2004 p. 440 or Gleitman et al., 1999, p494).

4. Which areas of psychology have or been or could
be influenced by evolutionary ideas?

Most areas of psychology have been influenced to some extent
by evolutionary ideas at one time or another in the last 150 years.
Clearly the area most influenced by evolutionary theories has been
animal psychology. During the last 20 years it has been cognitive
psychologists interested in perception and language who have been
most likely to point to innate mechanisms governing human cognition
(e.g. Fodor, 1983) whereas social psychologists have not generally
appealed to innate mechanism but rather to social influences and
social constructions (e.g. Harre, 1986)

One can make rough distinctions between the areas of human
psychology below:

Few would deny that “The sensory equipment of any species is
an adaptation to the environment in which it lives” (see Gleitman,
1999, p. 192). The same goes for motor systems — walking
upright, and using an opposable thumb, and consequent capacities
for eye-hand co-ordination, are special human characteristics which
can be related to those of our primate cousins.

b) Cognitive systems (object perception, early language,
grammar)

Apart from the sensory apparatus, there is evidence that the
human brain comes already equipped to interpret sensory information
in standard ways — “Do humans come equipped with some built-in
notion of space and objects? Some experiments with very young
infants suggest that they do.” (Gleitman, 1999, p. 552; “What is
the cognitive starting point?”).

There is a strong consensus among psycholinguists that human
infants make built-in assumptions about word use and syntax
(Gleitman, 1999, pp. 379-380: ‘Perceptual and conceptual biases in
child learners’), and that “the young child is neurologically
‘programmed’ to learn language.” (Gleitman, 1999; pp. 381-382).

Facial expression of emotions change relatively little from
culture to culture and Gleitman takes the sociobiological view that
the built-in features of human emotional expression serve the same
kind of communicative functions as displays in non-human
animals.

Sociobiologists are inclined to explain co-operation in human
groups as based on kin-selection, or on reciprocal altruism, which
are both consistent with the “selfish gene” idea. Critics counter
that while the capacity to have a culture may require a uniquely
evolved human genetic makeup, social behaviour within a particular
culture can only be understood in terms of cultural, rather than
genetic, rules. (Gleitman, 1999, pp. 435-6).

A slightly more abstract idea about the evolution of human
capacities is that human intelligence evolved as an adaptation to
cope with the complexities of social exchange rules in any
particular culture. (Cosmides, 1989; Gleitman, 1999; p. 494).

It is important to bear in mind that there is no moral
obligation to follow such biologically based pre-dispositions as
may exist. Gleitman et al. (1999, p.437; see also p. 426) refer to
a remark made to the character played by Humphrey Bogart in the
film The African Queen — “Nature, Mr. Allnutt, is what we
were put on this earth to rise above!”.

Many, such as Donald (1993), and the critics of evolutionary
psychology argue that the human capacity for
invention in a social context changes everything — even the
biological role of memory, because literacy means that the brain is
“externally programmable”, and that the internet and computer-based
information technology constitute another new stage of cognitive
and social change which is outside strictly Darwinian and genetic
evolution.

Conclusion: Darwinian evolution has shaped many aspects of
human cognition, starting with the capacities of our perceptual
systems, and arguably including higher-order aspects of cognitive
and emotional biases. But biologically based predispositions do
little to diminish the profound role of cultural and historical
influences on uniquely human intellectual achievement and social
diversity.

Reichert, H., & Simeone, A. (2001). Developmental genetics evidence for a monophyletic origin of the bilaterian brain. Philosophical Transactions of the Royal Society of London Series B-, 356(1414), 1533-1544.

Segal, L (2001) Main agendas and hidden agendas. The Psychologist, 14(8), 422-423 (available free at http://www.thepsychologist.org.uk/
Shu, W. G., et al.. (2005). Altered ultrasonic vocalization in mice with a disruption in the Foxp2 gene. Proceedings of the National Academy of Sciences of the United States of America, 102(27), 9643-9648.